A common threat to aircraft exterior maintenance for aviation is corrosion where metals are constantly exposed to the harsh environment of flying in the sky. Excessive corrosion can ruin your plane, damaging its structural integrity and making it highly unsafe for flight. On top of that, it can also decrease the value of your aircraft. Therefore, choosing the right corrosion inhibitor will prevent corrosion from happening in the first place. Once rusted and corroded, the metallic parts or systems can’t be used and pose risks, and hence developing corrosion resistance in any product, part, or system is extremely crucial for its proper functioning. So it’s important to keep the metallic part of the aircraft from corroding at the first place, hence corrosion inhibitor is what you need.
What is Corrosion Inhibitor?
A corrosion inhibitor is a chemical that prevents or reduces the impact of corrosion on an exposed metal of the aircraft in a harsh environment. Corrosion inhibitors add water or acids in specific concentrations to form a film or coating to the metallic surface of the aircraft, this, in turn, creates an inhibitor for the surface to protect it from the harsh environment.
Even though it might seem an easy concept to grasp, there’s a variety of corrosion inhibitors out there and each has its own application and factors that you might reconsider before getting a corrosion inhibitor for your aircraft.
Types of Corrosion Inhibitor
There are various types of corrosion inhibitors, each is more effective on certain surfaces or environments and acts as the first line of defense. Here are the types of corrosion inhibitors that you should know before buying for your aircraft:
Anodic Inhibitors
An anodic inhibitor is a type of inhibitor that forms a film at the metal-electrolyte interface to prevent corrosion. The basic principle of these chemicals is that it uses surface adsorption and form a thin film on the metal surface, that will innate anodic polarization properties to prevent corrosion. This thin film blocks the electrochemical reaction to stop the metallic surfaces from dissolving into the corroded solution. Chromate, tungstate, molybdate, and nitrate compounds are a few examples of anodic inhibitors.
Cathodic Inhibitors
A cathodic inhibitor also uses the same principle to stop the electrochemical reaction. Instead of reacting on the anodic ends, it reacts to the cathode end. Organic compounds such as calcium compounds of phosphonates and polyphosphates, zinc ions, naphthols, phenolic compounds, gelatin, and tannin are widely present in cathodic corrosion inhibiting chemicals. Cathodic inhibitors produce a non-conductor insoluble compound, which forms this protective layer over the metal surface.
Mixed Inhibitors
In common use cases for aviation, a mixed inhibitor is more ideal. Chromate, phosphonates, and polyphosphate compounds of zinc marry well as mixed inhibitors. These substances prevent the anodic as well as cathodic corrosion process. Silicates are also used as water softeners to stop the formation of rust in water.
ORAPI RECOMMENDS:
Multi-Metal Spray Wash Liquid
MAGNUSPRAY 205 is a non-caustic liquid wash spray cleaner, it is a blend of alkaline builders, water conditioners, and biodegradable low foaming surfactant and corrosion inhibitors. It uses include spray wash cleaning of ferrous and non-ferrous metals. Suitable for use at room temperature in many applications
Volatile Corrosion Inhibitors (VCI)
Volatile corrosion inhibitors use volatile compounds such as hydrazine are used to prevent corrosion in closed systems such as condenser tubes. VCI compounds are volatilized and transferred to the corrosion sites in a closed environment such as boilers. When steam is formed these compounds are transferred along with it to the condenser tubes.
Factors when Choosing the Right Corrosion Inhibitor
The right corrosion inhibitor for your application is all about what, where and how the application is being applied. Do not worry if you do not get this sorted out, we have the following questions to help you find out your corrosion inhibitor:
- What material will the application be applied on? (Does the surface have an existing coating, or does the metal is ferrous metal or non-ferrous metal?)
- What will the conditions of the surface will undergo? (harsh indoor, sheltered outdoors, etc.)?
- Do the surface need chemical resistance? (algae stains, acidic levels)
- Is my priority durability, convenience, or low environmental impact? (Depending on the environment in which the surface will go through, a tougher environment require stronger durability but will comprise the environmental impact of the inhibitor)
- What are your VOC requirements?
- Do you need the corrosion protection to last short-term or long-term protection? (Depend on your maintenance cycle)
- What is my budget?
What Happen if Corrosion Has Happened?
There are times when corrosion has happened and you can’t see it as it is hidden underneath the layer of paint. It only takes the layer of the paint to crack once, then it allows oxygen and moisture to get underneath and deteriorate the surface protection quickly. Typically, this occurs anywhere there is a seam on the fuselage, wing, empennage, or flight control surface. The straightforward answer would be to remove those corrosion-inhibiting compounds as soon as possible before it spread. To learn more click here. Or you can use CITRIKLEEN X520.
Still Clueless?
Click on the button below to request a professional consultant to help you get the right corrosion inhibitor for your application.
